Seadek is the company I got mine from... I got the small sheet in the 5mm thickness. The small sheet is a little short and too wide, so I just cut it in half, applied from the ends inward and used the excess to fill the gap in the center.

It works great for going barefoot, but I still tend to wear shoes anyway... just a preference thing I guess. I figured the foam would be better for those in the boat that just want to try out skating.

kaleb, have you tried grip tape? you should try it before you spend the money on foam. you will see that foam is super sticky and hard to move your feet compared to grip tape. and with grip you can feel the shape of the board much more